Progesterone in oil or PIO shots are a medication you are often prescribed when undergoing IVF treatment.
As this injection is self-administered at home, many women dread having to perform the shot — and a large part of this dread comes from the discomfort associated with PIO shots.
Are PIO shots painful? PIO shots can be painful due to the injection type and large needle size. PIO shots are an intramuscular injection, delivering the medication deep beyond the tissue just beneath the skin, and are commonly given in the sensitive gluteus maximus (buttock) muscles or the vastus lateralis (thigh) muscles.
There’s no denying that the pain in the butt is real with this type of injection! It’s worth remembering, however, that with each temporary unpleasant injection, you may be increasing your chances of having a healthy pregnancy.
Let’s find out why PIO shots hurt, possible side effects, and tips on how to make the injections less of a pain…
Progesterone in Oil Shots and Pain
Progesterone in oil (PIO) injections can leave you feeling pretty sore due to the sensitivity of the injection site and the unpleasant side effects that follow.
Let’s look at why PIO shots are painful, the right location for the shot, and more.
Why PIO Shots Hurt
There are three main reasons why PIO shots are often painful.
Firstly, these shots are intramuscular injections delivered deep into your muscles compared with most injections administered in the subcutaneous layer of fatty tissue just under your skin.
Secondly, according to IVF nurse Natalie Castillo-Rubio from Fertility Space, the PIO shot needle is larger and thicker than any other IVF shot, and the progesterone oil is fairly thick, meaning the injection itself can take time.
What You Might Experience
It’s common for your PIO shot to leave you feeling sore with some swelling at the injection site.
You may also notice small bumps or knots under the skin at the site — this is quite common and is caused by the oil accumulating in your muscle.
Upon your first few tries using a PIO shot, you may find that you miss the muscle layer. Don’t worry though as this can be hard to target, and we’ll explain how to get it right further on.
PIO Shot Side Effects
According to Cleveland Clinic, some common side effects from your PIO shot that are not a cause for concern include:
- Breast pain/tenderness
- Irregular menstrual cycles or spotting
- Mood swings
- Swelling in the ankles, hands, or feet
Some other rare side effects that should be reported immediately to your healthcare provider are:
- Blood clot – Chest pain, shortness of breath, pain and swelling in the leg, or a warm sensation in the leg
- Symptoms of a stroke – A sudden numbness/weakness in the face, arm, or leg; slurred or troubled speech; difficulty walking; loss of balance/coordination; change in vision; severe headaches
- Allergic reactions – Progesterone is commonly dissolved in a sesame seed oil base, which may cause a skin rash, hives, itching, and swelling in the face, lips, tongue, or throat in some patients. In this case, your healthcare team may switch you to PIO medication with a different oil base.
- Eye pain or sudden change in vision – Blurred vision, double vision, seeing halo rings, etc.
- Liver injury – Right upper belly pain, appetite loss, lighter (clay-colored) stool, very dark urine, yellowing of the skin or eyes, unusual fatigue/weakness
- Changes to breast tissue – Pain, redness, nipple discharge, or a new lump
- Sudden migraines or worsening headaches
Progesterone Injection Wrong Place
PIO shots are commonly administered in the buttock but sometimes also in the thigh, so with a relatively small area to work with, it’s common for patients to end up using the same location twice or more.
This can make the injection hurt a lot more since the shot may be going into a previous muscle knot.
For this reason, it’s important to always “…rotate your injection sites. Never inject your medication into the same spot repeatedly. This can increase your chances of tissue damage,” explains nurse and fertility author Nicole Galan.
Progesterone Shots Location
Choosing a location that feels most comfortable for you (buttock or thigh), your PIO shot should either be injected in the outer side of your upper thigh or the upper outer quadrant of your buttock (demonstrated here).
The injection location in your thigh will be the vastus lateralis muscle.
As for finding the right spot in your buttock muscle, the McGill University Health Centre advises you to imagine that one buttock is divided into four equal squares to help you target the upper outer square safely and precisely to avoid running into the large blood vessels in your mid-buttock area.
Check out the handy diagram and injection instructions here.
Progesterone Shot Missed Muscle
This is a hard shot to administer yourself, and some patients often miss the deep muscle layer. In this case, the medication will still absorb in subcutaneous tissue, just not as quickly or efficiently.
It’s important that the PIO shot goes into your muscle layer as this absorbs the oil much faster due to the increased blood supply.
A good way to ensure you are not missing the muscle, according to OB/GYN specialist Dr. Alex Robles from Fertility Made Simple, is:
“Holding the needle like a dart, insert the needle at a 90-degree angle to your skin and into the muscle.”
If in doubt, your doctor may offer a blood test to check your progesterone levels and see where you’re at.
Nerve Damage From Progesterone in Oil Injections
It can take a while for the pain and numbness to subside from the injection site, with some patients reporting tenderness for several months after taking the shots and long into pregnancy.
However, nerve damage as a result of PIO shots is relatively rare as it is difficult to hit the sciatic nerve straight on — even with a needle this size!
If the oil accumulates in the muscle as a result of administering the shot in the same spot over and over again, the oil can settle around a nerve, resulting in long-term pain or soreness, but nerve injury is only likely to occur when safe injection practices are not followed.
How To Make Progesterone Injections Less Painful
While your PIO shots will never be a cakewalk, there are a few ways to make the injections less painful from pre-injection tips to caring for the injection site afterward — check out the following 12 tips!
1. Warm Up the Vial Beforehand
The oil in the progesterone medication is more viscous when cool.
To help it thin out so it exits the needle faster and absorbs more easily, PVED (Parents Via Egg Donation) advises warming the vial to body temperature before use by holding the vial in your hands, between your thighs, or in your cleavage.
2. Try To Relax Your Glutes
IVF nurse Castillo-Rubio advises lying down so your butt muscles are not contracted, or if you have to stand for the shot “bend your knee on the side you are injecting and slightly lift the leg to take the weight off that glute muscle.”
3. Make Sure You Have the Right Spot
Some find picturing the top outward corner of their pants’ back pocket is a good way to get the right injection location!
4. Have Someone Help You!
A trusted partner or friend has a better visual of where to place the needle and helps take the anxiety of self-administering.
5. Ice a Small Area
Applying the corner of an ice pack to the injection site beforehand for a few minutes can make the shot a lot more tolerable.
Just be careful to ice a small area on the shot location (not half your butt cheek) as a large iced area could make it hard for the progesterone to absorb.
6. Stretch the Skin Taut Instead of Pinching
It’s best to give the needle a flat, firm surface to inject as raised skin layers could mean a slower shot due to wobbling around (plus, pinching hold of your skin for the duration of the shot will only add to the tenderness later).
7. Always Rotate Your Injection Sites
Don’t go into the same area twice, especially into a lump/knot as these need to heal first.
8. Put the Needle in Fast
Like peeling off a bandage attached to fine hairs, you’re going to feel that needle a lot more if you put it in too slowly, so try not to hesitate!
9. Massage the Area Afterward
Gently massage the shot site for 5-10 minutes afterward to get the blood flowing and ease some tension. It’s even easier if you have your partner to help!
10. Go for a Short Post-Injection Walk
A gentle walk right after the shot can prevent your muscles from feeling too stiff and help distract from the soreness.
11. Apply a Warm Compress to the Area
After getting your shot, IVF nurse Natalie recommends using moisture and heat to tackle the pain:
“Use a washcloth, run under hot water and massage the inject site. The heat and moisture will help the muscle to absorb the medication a little better than dry heat since the medication is oil based.”
12. Switch Sides Between Injections
Don’t torment one thigh or butt cheek; try to mix it up so things are not so obviously sore on one side of your body.
How To Get Rid of Lumps From Progesterone Injections
Lumps and knots under the skin should go away within a few weeks, but you can do what you can to help to prevent these lumps from your PIO shots by gently massaging the injection site afterward.
Applying microwavable heat pads or a moist hot towel may also help as it’s thought this helps to spread the medication over a wider area, making the oil less likely to lump together.
If you find that you are running out of space on your injection site (i.e. needing to inject near lots of previous lumps), some patients on The Bump forum found that using a longer needle helped matters.
Of course, be sure to discuss this with your doctor first.
The thick nature of progesterone in oil combined with the needle size and sensitive injection area can make PIO shots hurt, but with steps like rotating your injection sites and getting someone else to administer the shot, you can make the process less of a painful ordeal.
Pain and soreness are normal in the weeks or even months following these shots, but if you experience significant pain or any serious side effects as a result of your PIO shots, be sure to seek medical attention immediately.
Rebecca is a seasoned copywriter and researcher with over a decade of experience, specializing in parenting topics. With a passion for all aspects of raising children, from breastfeeding to potty training.